Rainbow Electronics BA6955N - Manual (Page 8)

BA6283N / BA6955N
Motor driver ICs
(5) Large current line
Large currents are carried by the motor power supply and motor ground for these ICs. Therefore, the layout of the
pattern of the PC board and the constants of certain parameters for external components, such as the capacitor
between the power supply and ground, may cause this large output current to flow back to the input pins, resulting in
output oscillation or other malfunctions. To prevent this, make sure that the PC board layout and external circuit
constants cause no problems with the characteristics of these ICs.
(6) Power dissipation
The power dissipation will fluctuate depending on the mounted conditions of the IC and the ambient environment.
Make sure to carefully check the thermal design of the application where these ICs will be used.
(7) Power consumption
The power consumption by the IC varies widely with the power supply voltage and the output current. Give full
consideration to the power dissipation ratting and the thermal resistance data and transient thermal resistance data,
to provide a thermal design so that none of the ratings for the IC are exceeded.
(8) ASO
Make sure that the output current and supply voltage do not exceed the ASO values.
(9) Precautions for input mode switching
To ensure reliability, it is recommended that the mode switching for the motor pass once through the open mode.
(10) Rush current
There are no circuits built into these ICs that prevent rush currents. Therefore, it is recommended to place a current
limiting resistor or other physical countermeasure.
(11) Factors regarding the thermal, power supply, and motor conditions. If the potential of the output pin sways greatly and
goes below the potential of ground, the operation of the IC may malfunction or be adversely affected. In such a case,
place a diode between the output and ground, or other countermeasure, to prevent this.
(12) Input pins (F
IN
and R
IN
) thermal characteristics
The F
IN
and R
IN
pins have thermal characteristics. Take these thermal characteristics into consideration when using
the IC.
(13) Thermal shutdown circuit (TSD)
When the junction temperature reaches approximately 170
°C (Typ.) during operation, the driver outputs are all
turned off.
There is an approximate 20
°C (Typ.) thermal hysteresis.
(14) Motor noise
To eliminate motor noise, connect a capacitor between OUT1 and GND and between OUT2 and GND. Alternatively,
connect a capacitor between OUT1 and OUT2, and also a diode between OUT1 and GND and between OUT2 and
GND (see the figure below).
OUT1 OUT2 OUT1 OUT2